SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '86db9bb39960772154540d125209dbf28e3652acc7b29f3e3d647c4fa8058359' 
  AND token = 'LjJ8x6tC6xVeg2HBaphn2lxYW1L74126GIfgYgW1tBk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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