SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'feb42bbf5d629a98846f7e8c61095c345611117bdfc7aff5d01ed3a98c0fa9d7' 
  AND token = 'Z/Ub3DUgwNW+hfkLJ6Rfz2gKwG4/o7nfyDHzHkrAgJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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