SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '581859277ce9b49539dbdd32d32808534af233a1722c162ea9207287074b8ec1' 
  AND token = 'B/hOggVaRZ6BezgCFGJQqHjihlxqTiAesY0VPaNz2VQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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