SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe5c9e26d9e02ac22b15ef73aa647183935f0ea5436c7b7e16b31dc4790698b0' 
  AND token = 'FH8eb2vOHiMnChY9lTQgglfzZTgW8UdyIbSMg8ZokDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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