SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6fe5171ccc18fc9c5c2759cc37440a467c279a62cbff69b02dee7aad7ae1bad8' 
  AND token = 'jIni4plpwVqqCIXfCyeLCsDG+kWhSy+plzTuqdforoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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