SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '418d034d57cd7d38c28dff6bde05d5f22e3030a1a26a24f2ba74151a76dce293' 
  AND token = 'pYdrmImtHYh50QEgX1YOgNs/qP8uaMABSCVQucq54DY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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