SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce6403f9ac26398e787424991783a788f5d7aee767675e34e07a010abc692096' 
  AND token = 'vVjeTrfHHDjL7EW5Yvto1u6N+w4C1O7YD2sOk8nMlsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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