SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9bc0b3dcdd8828ab8e44c17646e4090b187db7ab3edf9485782d85fbff12ec82' 
  AND token = 'qQeWMOPAwOzBSOuHqISEUB/fllbwIPidJzVRRBvWI+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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