SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8fd471c2bb15655b63c4e47806219ca31d7f291b57baaf67fb379600335f6414' 
  AND token = 'n/XYuULbZkJTEV2+jySK2O6rl52wBH/CIB5hdKCEJI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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