SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53fab70f87d9ec0056ac1d81589b2afa8e1afb87b8805ba3e2fe40da84003516' 
  AND token = 'XJMoESAfmOqWtAJGOHe5o/IKS5xAKRaJTPEVSNRE7l4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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