SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '24348ba1daa14c04ed2325d3e2ffeab723737df454288b16e6593e7e59409b01' 
  AND token = 'XM6xFGWamBUrLPbmlBd1cuFCSMf9lbdP64TfBL+EUx4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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