SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec689bdf75ba466eaa2f1cfaba67127c4587c498d697996ec3e0a67b812b9edd' 
  AND token = 'W51dUrewd8xDonxy5IAV9Sot9wboTzKhfUvfY/tQfqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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