SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc0e42f76dd938b0a595fa43aab2252ec265f9174d88b16457bf64da7d79697e' 
  AND token = 'byTiB7YxwpckbneyX67g6fuTNXmGh+nUcvZdjVoKDKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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