SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f18e77ea24a59752829d4001c78a194117d028795f7080f62f4ae79db33efe93' 
  AND token = 'okAAEj6nfXRyErQu7ukjFowrioTJTfCmEv7Bb6z6h4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}