SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd26d674490a69596febe5e137e3dcb845c1ca495655265911a7f5fc6cd237705' 
  AND token = '0nSptCgYvYQVhvoGXsTBz1uuvRGIC+NjzFsbInCgCLQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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