SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4edbeb92dac7c157037045c4ba10717407ef389ff25a94685563c985707d3f89' 
  AND token = 'VA6pihuVuFEVSMVPY6aHZeVYlKblugdEa383jbvzQ+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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