SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb4263f5d90297d59c60b0b165a73e81168d45a9919ed97bb229912cdae5779a' 
  AND token = 'ewQ41qaS+I3qfPXbRYmVC3KdeffOuS8ie3Mh3iHINNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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