SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2b0ce391b4ed39f383ad4b515a52a6c03ba7b4a85017781d111a91565fd9556' 
  AND token = 'F3+xUv8gXPLI5zS8mIiJWPDhV7vm6MhhXRxgf8N/Z4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00104

JSON explain

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