SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '939b0003b859d67df604c98411def13962309804e789a17b9322dd8b282cf4ad' 
  AND token = 'nmUjd9ISUYZBfpJBQIYrPyAnimDSQM91bRQkc64jCy4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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