SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9bc502858d99edf6429f8776bd522ee03e22a461b12ca9210d710cdc317dac1' 
  AND token = 'eh1wNaBOEWHfjW5n8U7ck7rP/aGZx9F0rF1IS6ae7Y8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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