SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c481cf1ff207966ec398e42bda8bf805478368ea546719094f6bc2774ca980d' 
  AND token = 'Dv9Y5HPcj2HTGTCMzJUAyjEkf+SBB4mdzqSrBOu0IFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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