SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfb8cc8e31a02bbbbf5b611a7fe047296836741047212742364185734bf5e1b2' 
  AND token = 'mJCnPRo9Rr5kth4NRy22nLnF2ROP4ajyf75rJzVlVIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00075

JSON explain

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