SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '707de3c348c458d4e03a48b4ef07736128038443cd68880e54cc14cf230540b9' 
  AND token = 'zXfJlsRGdxAI4pPecUWrj4aVkqmB4wVL9j09SwcjvcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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