SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '796f4d67e76f3b466c32c58b759b0b726fef4cd529f64216cd3519ad7c822764' 
  AND token = 'lmDnNwa49oQz9IzjXwoXLedPAze1qxYI1/kU1wwx+YA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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