SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '063358cc1eeaf78b683d26b135e56747847e09cfe29b2207f1082529420404f4' 
  AND token = '9mNJaJj+/IYzD58pBFJnbqE/gfpQXfkRjy0lHy1aQJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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