SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed32cac02081173ba2d1bfd76138384b1211a5f14a094d37abb0260983af6442' 
  AND token = '91MjoPbLHn/6ZtfQ5+ZLNhjuPK//5Zpxi+2buPlU+/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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