SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7840cf3d95b358d3bb55bbce9ca8de5334d13fc6302b8d71df1c389d6cbe50eb' 
  AND token = 'ellW9tU1lqIu920gf3ov9OTK5KJzXQVPRKvX5TsxX5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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