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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce35953cf3e5a33d08ef9b3c7e655fe3ddb8eeba7f2797e72850a607b95f2a51' 
  AND token = 'th6vpxf4/RRTJOfHfmYVPqnQchIrAiTGhdwKb3sVTDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}