SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd091bc59b948845ca727195e1ac51b544cf17086aa05e9fea0a54391cd7364b' 
  AND token = 'ydRSUo0fyoy3pwpdntCKm0Qc98bXPFf8f/Hrlt8Kbbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}