SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a0d5233c028f1db199b8401aadbce383a41881bcb04c71a2a88121e95230172c' 
  AND token = 'MG9y8sxs9x4g7ja+ZwjURv9yEtItZTSNItkisU2Nipw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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