SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '032b76e632161f57a96b6160a2f88b64458fcbf11989a3f745592b530fef2e3a' 
  AND token = '5cCOF1wcPBCrnUnykaRD9XiwS6sv/2K1Va4orEKYv3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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