SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '901e5dcc8e9998bc7db874f51528f1ea56d326303451b44f3eaf378711a2ec98' 
  AND token = 'y2RpA8ZfOCXwNvul6Butz+4bks7MadNaqAdDqq4Mkho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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