SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a30933955ba92428f0c109952c6c853c141b254e4240d712a189a7d3e734c11a' 
  AND token = 'ccRN4OnChlxJYWsozjJMkWLpdFh17OZWwqXMEg4GNgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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