SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '054c6f08d74740f518c135fc71740a0f361d8a947bf52b5bf99942a0bc4117d4' 
  AND token = 'h59WJxpnVoHRUrdXasr8DxMyAe79lfGKOCdzPOBmzUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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