SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a1c4eab2f10513310848174c2582905e5a6db8554c8edf75a3f7536c19bdbe47' 
  AND token = 'x6XHhA4/xfAsZZ0Z7j8oKkfYHjIuKXrB0FhP1eKvafg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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