SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c810031fcfbf4a98a3469405951c540f0c7da734a56955c0c6a29946e5d921c6' 
  AND token = 'OjVxG0YEKfvDr9WyPazzEVchECW52ApN98rK+DBqYNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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