SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cd0eb376b01c9b3d0b5cb2a4f19658e0844ca8c3b8a93989467a03c9f53eb25' 
  AND token = 'Yg+5HeuajVZKCrHYinXBwnMZgFbg1iPO/PRObGcJta4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}