SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e085b7bbfe8ffbee016cab98f4b85066a90380206c7b1df9fbc56cb79253061b' 
  AND token = '+cPMVD605A+yTqKdPRJvrVU0cgDfNLYx+sBGakNecho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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