SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cda60d343f3431b487779261cade333e4a9b7a21681328c5da7f74d6f2849254' 
  AND token = 'TUGIVKt0lx++FAPfMMFCAhmgvHKa+PYe3g5BHwtR4ow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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