SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5214eeefe7b7114bf026769ae1775ef32cc8d2a81d8c83dd1e64cf4806e0b43' 
  AND token = 'koAyZK34A8oF8tVaZFgAPeNMss8Nh2tdwP1jkYjnTYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}