SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38365518c5bd36c1dd961d94e54ce307927932d02b401074a9c1282c7ada3cef' 
  AND token = 'fPkYjNQrH9mwskEYIG3VPsfX9jpaO8grwjJDHMliXjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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