SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15ee88eb9afdacdd92c00cd12464ca0b1062b33ac7ffb990d496531de3534557' 
  AND token = 'yBDBIut5Qphh3wQkfE3ifX8Bd4zZPLZdwdwUTOsFw4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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