SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8002b7adcda1193243c2800e664349833b43a524ee39391ae82c42fe81d3ef73' 
  AND token = 'NCfiWASl7YydQRXRs6lN5Xgte0TPICsxtlsuH7+AmeU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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