SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '487803cfa136c7ea5d4655402cc58be7c30891414a9f411ea82a49cd16b12e13' 
  AND token = 'hvkAuLwp+XkO6rhPJwGx1H17z/DFynm2EXOQY2juw4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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