SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bcf75f135d45ac9f171bf2b9f937946ff5664d22295585197f7dc4b9f783bbc' 
  AND token = 'g8FWZ817bTPGKGqNcMPQGi42X1Xf8+7SjGLqxLlJMm8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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