SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae36bee2e701aea9d320a504c5d0f03c112b2ecb781314df7e71158dbdccf38e' 
  AND token = 'AfjkmrDJkNecU+qTBEDg8gP/S+kanOBmOz43TeG90N8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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