SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '047d65dca3045fb5fbc764944dcdf39f8b30830dd4300cc5fffc98d98b06744e' 
  AND token = 'oU8kD4GRZup2fX9MK8AkMKdL+Elj8JRmZsyyq7ZeDEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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