SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'deadb51b0f1619a18155c69d88685b2f638624403e26535de99dcf8d6f4a6689' 
  AND token = 'HpDtuSMoTls5pAyQnunq6mVqc3uZFhzi9CVAOKmv5DI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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