SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd07c38178051425ef43481c26d8754af92fe85d8ba1e33aa85e85100cf1fee79' 
  AND token = 'uUrDBQL8nXP1pRFyG5D+QGqahsqninY5m2rHJWkNVUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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