SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5f8338252d29ce04694feb50b8a2cbb744a13cb575764df1bb8ea9e6b355d05' 
  AND token = 'ky0zKWVJfOTBtwzJCmzmkwIlsZ5HCbEL/udrY4lx7z4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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