SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5eb80179da50a3b7c5531cd733a5b750cb28445867540db1f8c193a1e37aff4c' 
  AND token = '5CAsKlvx8EhOL0YCybhGFOkgrQEalQDNddL7ov36I3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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