SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82f5fb72b3fd7b8a550018cb697f8875bc32aeb8e7da68c70ec6c610b1787ad9' 
  AND token = 'leVp/O5duK6tG+U6Yv2NGnTzY2ixfn32IapQvOvGjzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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