Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd520b4ffa69f7ff4ea704bec61cd0e1c78c1cfd28e741af3779c07c9d46c6ff3' 
  AND token = '/XlEjLkqZMoZDynUPeAxMxT7a4k6A3iPFvHRDhWjVeQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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