SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4efee536cbc28ee455b4beecdead34fd8c7e76b2e11f242e467c46d2f46d67b' 
  AND token = 'VkgX6pM5nZTnjn88CRcFN7/NYnM+xgkMMNAgtgUhwdU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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