SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '979b887bdd43bf4dba0a8de30bbc31c3e8f543e8f517da5498c536271738c1d0' 
  AND token = 'n6f/1YjaJ6rfgT9dEk0A2I+T8npCTGxpqqhZmQtjO1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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