SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20499a1cd222db2d4677997dac63c050229e932fc27bd4405f8b3e13556e7372' 
  AND token = 'PcwKxWRoPBQZflhWoP3mse420RWuXZPtZdMZ3Nxaj9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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