SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebb3b32d77ecf6f550ffb085465d253cf4641eb8eca85f38a81363884d2c8e80' 
  AND token = 'bxJQFWoSFPqHgHvclUGwLuGtwhKD0yAH5DngnRpQMag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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