SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '132848ed7262622a3b2723eb65bcc3543a31808e56ba4c2d49954db74dd29543' 
  AND token = '5EcYqCikh9p2HiV+nEWbmZoarVaySzOBmd3Pihotj2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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