SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1ff8244bc7981be37ae7eb0f4b51090a2bc2ed67da972e349fcb62f61aca992b' 
  AND token = 'LyunwXAom4ZaLK4VLWUZqhCBh+qt0y2veKj4+p0YS6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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