SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'beaf9363a32844f00812bce2a3d2fe0d412f98aa8cddb2fee165155ebb1e2d4a' 
  AND token = 'DEXj0E4/XORVHpYHbjbm/QQrQ/7jTvIxQ8a5EOls7Mk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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