SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e6d3daa2e2db3461988062f07bbb6f647c7bc63798a0d663343099e46b6936d7' 
  AND token = '40c4p8AN81ahNspO3YbndPbQwhcL/4V8ybwA6/L/mCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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