SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38eb3f01e96e0d332b616f70e8ff8b26828b7befe73e9be1f2ffddd4d75ffabf' 
  AND token = 'NCgYN2VPkr7ZoWzkmMUoejqu6KQM0+s7va0L1lKzJkQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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