SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '527b0dfd5768b1176f2c69e8c2d773a04ac835c1189cdb7d008574155e7cc83c' 
  AND token = 'FEWUPLAIWTm69kZZBvonHqFx+M2ivLBMivPW/3MQ5N8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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