SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5bb72b7ff12b2d768d226899f9023e82ea66e7da336de83ff091b982905bc788' 
  AND token = 'gxLMZuDXZngTiwq4vf6u8AgfNGrdmtgk5VLd7ZWz1C4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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