SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '429aafaaf9436f119700ca7ac6f704c500d0e30c596e846508d8b03b850cbb16' 
  AND token = '1NRHEnqfgrPDZ34fXx902tfwKKWBLbRLlXzKvVKTe+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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